I saw this sticker on one of restauranst in the City. I am curious about what it is and checked it out. According to the City of London website, City’s Community Toilet Scheme (CTS) is to provide toilet facilities available to the public with partnership with local businesses, supplementing the City’s facilities. In exchange for providing free access to toilets to the public, the City pays a ‘contribution’ to participating businesses, though they still retains the right to refuse admission in exceptional circumstances. There is no details of ‘contribution’ means, but maybe money? Anyways, this scheme brings win-win to everyone involved. It is reported that people using their toilets often do make a purchase, though they don’t need to buy anything. You can check participating businesses on their websites.